At first glance, all these struggles seem to equal the problem itself. Stop acting-out, goes the theory, and life will be cured. And the sad truth is that... as difficult as this may seem to many of us... the real truth is even trickier.
I think whatever is making us want, crave, indulge in, chase after the stuff we do... has something deeper behind it. Maybe: the "need" to have something. The thought that getting 'a little' will make life workable. The idea that I am entitled to it, or can't get through the day without it, or... whatever.
After a while, this work seems to boil down to what Hashem wants us to establish as the main focus in our relationships with other people. We shouldn't connect with them as objects, but as our beloved. Not desired for mutual objectification by consent, but for something mutual and real. So somehow, the victory over the shmutz has to include the ability to look deeper.
Ultimately, it's not about giving gratification to ourselves, but giving gratification to others. (Recall, the shoresh of ahava, 'hav,' means to GIVE.) We can't keep fueling ourselves alone, and can't nourish ourselves from self-generated energy - that's like connecting the air intake of our car to its exhaust pipe. We've got to CONNECT to love, and not try to recycle our own energy with our own hand.
Ninety days to no acting-out is one thing, but 90 days to becoming a more giving person is trickier. It's also clearly what HKB'H wants from us. Meaning that it's possible to get there. But not easy, yet.